1. Field of the Invention
The present invention relates to a path switching control system and a path switching control method for controlling switching of paths which connect units (apparatuses). The present invention also relates to a computer system using the path switching control system.
2. Description of the Related Art
In a computer system or a communication system, which includes active paths and standby paths, if the system detects an interface failure on an active path, it generally controls path switching from the active path to the standby path. For example, Japanese Patent Laid-Open Publication No. JP10-276205A describes an ATM communication system in which STM communication equipment controls switching to a standby interface apparatus if a fault occurs in an active interface apparatus. U.S. Pat. No. 5,721,727 discloses a technique for switching to a reserved path if a failure occurs on an active path.
When the system including active paths and standby paths controls the path switching, software processing controls the path switching from an active path which has detected the failure to a standby path. For example, in case of switching from the active path to the standby path due to an interface failure, the path switching is conducted using a software routine for failure management. In this switching, the path which has detected the failure is inactivated and the standby path is activated.
However, the path switching through the software processing wastes processor time and causes access to an interface card by the software. Therefore, it takes a long time to process the switching from the active path to the standby path.